BPA and its manufacture in the prior art is described U.S. Pat. No. 4,950,805 (Iimuro, et al.), U.S. Pat. No. 5,345,000 (Moriya et al.) and U.S. Pat. No. 6,806,394 (Evitt, et al.), which patents are incorporated herein by reference.
BPA is produced commercially by the condensation of acetone and phenol over an acid catalyst and, in fact, BPA production is the largest consumer of phenol. Currently, the most common route for the production of phenol comprises a three-step process in which the first step involves alkylation of benzene with propylene to produce cumene, followed by oxidation of the cumene to the corresponding hydroperoxide, and then cleavage of the hydroperoxide to produce equimolar amounts of phenol and acetone.
The production of BPA consumes two moles of phenol and one mole of acetone for each mole of BPA produced. According to the present invention, an integrated process in which part of the required phenol is produced from cumene, and part is produced by a heavies cracking stage, yield of the overall process is improved economically.
In the manufacture of BPA by current procedures, residue comprising some phenol, BPA and BPA byproduct is lost, usually being used as a fuel component. In the present integrated process, typical BPA byproduct residue losses are converted to phenol that is recycled and used in the reaction with acetone to reduce the overall consumption of phenol in the production of BPA.